As shown by the attachment, i'm presenting multiple images on a computer monitor. I can physically view the very first one that is presented, but on the next trial, the texture's I've drawn are done correctly, but they do not appear on the display itself. I know they are done correctly because I used Screen('GetImage') to obtain the copy that you see attached here. So i'm not sure what i'm doing wrong. I'm used to using offscreenwindow's, but here i opted to draw textures on the onscreen window. This is a psychtoolbox problem. 
I'm using this code to upload the image, make a texture out of it, and draw it to the onscreen window
img = imread(trial(t).nontargetImage); img = imresize(img, picResize); [iy, ix, ~] = size(img);
txtIndex=Screen('MakeTexture', expWin, img);
Screen('DrawTexture', expWin, txtIndex, [],...
[loc(i).x-(ix/2), loc(i).y-(iy/2), loc(i).x+(ix/2), loc(i).y+(iy/2),]);
and on trial 1, i'm seeing that the below appears correctly with the following code
[startRT] = Screen('flip',expWin);
But when trial 2 comes, and the expWin gets drawn to again with different textures, the expWin, when flipped, does not show anything at all (or at least i cannot see it). All i see is a black screen.
